running the 540's today, after running about 80 miles came to a no wake and brought them down to idle,one motor ran a little ways and then just shut down,all the electrical guages stay at the spot thet were at when it quit, after it cooled off about 10 minutes, they rpm guage went back to 0, as i had the key on .the motor fired right up, did this same sequence 2 more times before i got to the trailer about 5 miles. at first i thought msd box but that doesnt seem right, checked for loose connections and everything checks out tight and no-corrosion. i was tinking maybe the starter internally?
any suggestions?
thanks

Something is shorting or your batteries are toast. Check the water level in them.

Other possibilities is your belts are slipping for your generator.

Wannabe

new batteries 2 weeks ago, and the alternators are putting out 14 volts, and the other motor has no problem. this motor starts right up after cooling down 10 minutes, i'm starting to question the coil

Something is gettinfg hot and shorting out. I would start switching one thing at a time between engines. Coil being first.

swap coils between the motors or just replace the suspect one.

found the problem !! the short wire coming from inside the starter motor going into the solenoid was loose and causing intermittant loss of voltage, because it is the wire i never touch or hook up anything to i never suspected it as its a factory installed wire